O2 sensor wire connections.my original o2 sensor adaptor got melted by my exaust,so it was cut off the original wiring harness which had 4 wires which are red/white, orange,grey/white and grey. But the connector

If you've replaced the sensor twice,cleared the code and the code continues to reappear, either the harness wires between the o2 harness plug and ECU are suspect or the o2 circuit itself inside the ECU is suspect.You can test the wires that run between the o2 harness plug and the ECU itself by disconnecting the harness plug that comes off the o2 sensor and the plug from the ECU then test each wire by touching the red multimeter probe to one end of that wire and touching the black meter probe to the opposite end of that same wire with a meter set to read continuity/ohms.2.0 ohms or less indicates the wire is ok.Do this to each o2 wire.
You can also test for a short between two wires in the same harness by touching one probe to one wire & touching the other probe to the opposite wire,on the same end of each wire.This will reveal if a short is present from worn insulation between two or more wires in the same wiring harness.The meter should read a very high ohms value or OL if the wires are ok.If not,it indicates bare wires are touching each other.
When testing a length of wire for continuity,the harness plugs at both ends of that wire have to be disconnected in order to get a correct reading.

You might be able to, but it would be difficult. Is there any wiring left of the original wiring harness? If there is, I would suggest finding a 300m at a wrecking yard and cutting off the wiring harness part that has the connector that goes to the 02 sensor connector. I will attach a picture of the wiring diagram to the 02 sensor. Maybe that will help.

i would go buy a factory o2 sensor cause the aftermarket ones dont work that well anyway and the factory one should have 4 wires and of the same color

Its possible that plug is for an option that you particular model doesn't have, lets say a downstream O2 sensor(after cat).

Just cut and splice. 1 black wire, 1 grey wire, 2 white wires just color match. You may want to remove the upper intake plenum to gain access though. Might as well plan on replacing the o2 sensor while your at it. If the plug got melted because it rested on the exhaust manifold, you probably wont get it unplugged. Not sure where to obtain a replacement plug though. You may have to hit some salvage yards.

CausesPotential causes of an P0160 code include:

• Holes in exhaust near post cat o2 sensor
• Bad Bank 2, position 2, o2 sensor
• Wiring problem, melted harness, broken connectors, etc.
• Bad PCM

Possible SolutionsIt's always best to do a visual inspection of the exhaust system first. Look for holes near o2 sensors or wiring harnesses coming in contact with exhaust components. Repair as necessary.
1. Start the engine and allow it to reach operating temperature. Using a scan tool, observe the Bank 2 position 2 o2 sensor. If it isn't moving at all this doesn't necessarily mean that anythings wrong. Post cat o2 sensors often switch very little. Increase the engine RPM to a fast idle and then recheck the sensor voltage reading. If it starts switching now, the sensor may be sluggish and/or intermittently going "dormant". Replacing the sensor at this point would be a good idea. Visually check the o2 sensor for contaminates, etc. If you suspect it's contaminated with coolant or oil, replace it. But, if it still isn't responding after increasing engine RPM, turn off the engine and unplug the 2/2 o2 sensor. With KOEO (key on engine off) check that there is 12 Volts battery voltage and a good ground to the o2 sensor heater element. If the heater element has no battery voltage it can cause the o2 sensor to be sluggish and not switch properly which can cause a P0160.
So, diagnose that problem first(there will usually be other codes present). If there is power and ground to the heater element check that the sensor ground is present. If it is, connect a jumper wire between the sensor ground and signal wire. Now the 2/2 o2 sensor reading should be low. If so, replace the Bank 2 position 2 o2 sensor. If, after connecting the jumper wire, the o2 sensor reading still remains "stuck", check for wiring problems, harness contacting exhaust components, or broken connectors. Repair as necessary. Then recheck. If you can find no wiring problems and the o2 sensor reading on the scan tool doesn't change after installing the jumper wire, recheck at the PCM connector. It may be necessary to clip the signal wire near the PCM in a location that will be easy to repair. If it now shows a low voltage reading, then you know beyond a doubt that there is a wiring problem. At this point clipping the offending wire out of the harness and running a new one may be your best bet. But If it still shows no change, the PCM may be at fault.

There should be 2 ways of doing this. Get a portion of the wiring harness off a wreck or see if Ford can get you a new wire. Someone else may know more about this but some wires have heating elements in them and some may have resistance in the wiring. A plain wire would not be the same.

You sure you have the right harness you are trying to attach to? Most have 3 or 4 wires. Heater wire, ground, and signal wire. The 4 wire setup has two heater wires. I don't believe they make a two wire o2 connector because it wouldn't have a heating element or signal wire, has to have ground.

Grand Cherokee oxygen sensor locations for 4.0 and 4.7 engines







Four wires (circuits) are used on each O2 sensor:

• 12–volt feed circuit for the sensor heating element
• Ground circuit for the heater element
• Low-noise sensor return circuit to the PCM
• Input circuit from the sensor back to the PCM to detect sensor operation

O2S Sensor removal Never apply any type of grease to the oxygen sensor electrical connector, or attempt any soldering of the sensor wiring harness.
WARNING: THE EXHAUST MANIFOLD, EXHAUST PIPES AND CATALYTIC CONVERTER(S) BECOME VERY HOT DURING ENGINE OPERATION. ALLOW ENGINE TO COOL BEFORE REMOVING OXYGEN SENSOR.
1. Raise and support vehicle.
2. Disconnect O2S pigtail harness from main wiring harness.
3. If equipped, disconnect sensor wire harness mounting clips from engine or body.
CAUTION: When disconnecting sensor electrical connector, do not pull directly on wire going into sensor.
4. Remove O2S sensor with an oxygen sensor removal and installation tool.

02S Sensor installation
Threads of new oxygen sensors are factory coated with anti-seize compound to aid in removal. DO NOT add any additional anti-seize compound to threads of a new oxygen sensor.
1. Install O2S sensor. Tighten to 22 ft. lbs. (30 N·m) torque.
2. Connect O2S sensor wire connector to main wiring harness.
3. If equipped, connect sensor wire harness mounting clips to engine or body. When Equipped: The O2S pigtail harness must be clipped and/or bolted back to their original positions on engine or body to prevent mechanical damage to wiring.


Hope thats help (remember comment and rated this).

there are two 02 sensors actually on the engine. bank one is cylinders 1 3 5 bank 2 is 2 4 6. it controls the fuel to air ratio, if the O2 sensor is not working, the engine goes into limp mode, which means it is just putting as much fuel as possible into the cylinder, which will effect your gas mileage.

The O2 sensor may be fine, the pigtails off the 02 sensor go bad, the connection. I had in my car, i change the 02 sensor twice, then I found someone said the pigtails may be bad, so I cut the cars wiring harness pigtail, and the one coming off the 02 sensor, and directly wired it with the original truck 02 sensor, and it worked. all 02 sensors look similar, they screw in the side of the engine, and just have 4 wires coming off of it.

Try your origional one, and just bypassing the original wire connector, what I did was cut it off, skinned the wires, put some heat shrink rap on it, combined the wires together soldered them together, and heated the wire shrink rap, so that way it is water proof. car works perfect now.